Means for the production of load-carrying surfaces



Wm. 25, 1923. EJ473395 G. F. UNDERWOOD MEANS FOR THE PRODUCTION OF LOAD CARRYING SURFACES Filed June' 19. 1923 Patented Dec. 25, I923.

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GEORGE FREDERICK UNDERWOOD, OIE LONDON, ENGLAND.

MEANS FOR THE PRODUCTION OF LOAD-CARRYING- SURFACES.

Application filed June 19, 1923. Serial No. 646,401.

- England, have invented Improvements in or Relating to Means forthe Production of Load-Carrying Surfaces (for which I have filed application in Great Britain Novemfber 28, 1921, No. 31,757), of which the fol-- .lowing is a specification.

The problem of producing load carrying surfaces capable of a wide range of usefulness has received much attention, many factors having had tobe considered prominent amongst which may bev mentioned initial cost, durability, reduction of noise, absorption of vibration, appearance and so forth. I-Ieretofore no means has been proposed which can besaidto be entirely satisfactory on more than a few of the necessary points, and the general. object of the present inven tion is to provide improved means better adapted to produce a supporting surface possessed of the requisite properties for any particular purpose. 7:

To this end he invention consists in the employment of single block units of a base material at least two vertical faces of which are completely covered with anothermaterial of a substantially resilient character applied thereto in the form of a relatively thin layer. Such base material may be a natural product or one artificially preparedand the material to be applied thereto may be any 'Mifilin & (10., Boston, publishers, 1884. By

suitable grade of raw smoked rubber in preformed sheets.

A. popular method of road construction involves the use of wood blocks. A-specially good roadway is obtainable on this plan by employing blocks capped with a relatively thick pad of rubber which is sometimes extended'partially down the sides but on account of expense it is not at present generally adopted and the more usual practice is to employ plain wood blocks laid in rows with intervening spaces, a molten bituminous or like medium being subsequently flooded over'the'blocks with the intention of filling the interstices. In this, however, there is no certainty that air pockets will not form, whilst it is furthermore necessary to scatter over the flooded blocks material of a granular character. This granular material is subsequently forced by the traffic into the blocks and consequently to a certain extent destroys the fibre. According to the present invention wood blocks may be employed similar to those ordinarily used, and it will therefore be further described in th1s connection with the aid of the accompanying drawings wherein Figs. 1 to 7 are perspective views of various forms, Figs. 8 and ,9 are plan views illustrating blocks according to Figs. 1 and 2 as set. Fig. 10 is a side elevation of another form of block. In Fig. 1 is a block to the longer side faces only of which are applied layers 6 of raw smoked sheet rubber, if it is desired that the wood blocks should make direct end to end contact. plan however, is to envelop both the sides and ends as shown in Fig. 2, thereby serving to compensate for lateral expansion and contraction of the roadway as Well as that in a longitudinal direction, Such blocks are laid with the rubber covered sides or sides and ends in contact asshown respectively in .ers, 1880, and also on page 771 of Knights New Mechanical Dictionary, Houghton,

appropriately selecting a grade of rubber to suit the hardness of the wood block, uniform wearing will result so that there is an entire absence'of ridging such as is found in roadways laid with rows of soft Wood blocks separated by narrower hardwood blocks as is sometimes adopted. The known destructive effect of wheel pounding is consequently absent or minimized.

Other advantages derived from this method of road making are to be found: in the possibility of lifting and relaying the blocks What is considered a preferable inverted, there being no labour involved in cleaning the blocks of adhesive with the tendency to damage and necessity of frequent tool sharpening. Blocks furthermore after the rubber is applied thereto may be stocked for some time so protected against weather as to avoid substantial warping.

The rubber, of whatever kind, whether it be raw or compounded may be intimately attached to the wood blocks in any convenient way such as by any suitable form of vulcanizing including the Peachey cold process, either in advance or during the laying of the blocks. The vulcanizing can also be supplemented by applying mechanical holding devices such as metal studs or staples as shown at 0 in Fig. 2 if desired.

Should resilience in a vertical direction be desired the bottoms of the blocks may be covered with rubber or the like, as shown at d in Fig. 3.

For other purposes where a rubber surface may be required blocks of wood, concrete or the like may be enveloped on four contiguous sides as referred to but laid so that the two remaining opposite and uncovered sides 6 are vertical, as shown in Fig. 4C, the said sides 6 of one row of blocks contacting directly with the uncovered sides of an adjacent row or rows.

Such an arrangement will be found advantageous in the production of a driving stance in golf couises, for example, tennis courts, machinery foundations and the like.

If the rubber is wrapped around the sides of the block the edges will be somewhat rounded and where this is or maybe disadvantageous, the rubber may be wrapped around three sides and terminate sharply with the fourth side or top as shown in Fig. 10 which can then be covered with a perfectly flat layer f of rubber so that a number of blocks when assembled, present an even and continuous surface.

Tile-like blocks covered in any of the ways referred to may be employed for purposes such as flooring, steps and the like, such blocks being formed with male-and female stepped edges enabling each to be individually nailed or otherwise secured to a foundation, the rubber of the various blocks being variously coloured to produce different effects. An example of this kind is shown in Fig. 5.

Or as will be obvious from Fig. 6, blocks actording to the invention may be threaded singly on to a wire or wires whilst being laid, or laid in rows comprising a number of blocks previously threaded upon a wire or wires. Or the blocks may be connected together in other ways such' as by providing them with spiked devices 9 or the like as in Fig. 7 adapted to be driven into place.

The thickness of the rubber may be varied to suit requirements and may be smooth, or

of a roughened character.

I am aware that it has been proposed to manufacture fabricated boards of a layer of cementitious or non-metallic material to one or both sides of which i applied a layer or sheet of another material such as asbestos or other paper, felt, or fire-resisting fabric but these are applicable only for general building purposes. No claim is accordingly made to any such board nor to composite blocks comprising vertical layers of resilient material interposed between three pieces of wood or the like bolted together and used as a border for floors to compensate for expansion and contraction of the latten What I claim is 1. Means for producing load carrying surfaces comprising single block units composed of a comparatively hard base material having a plurality of its vertical faces or sides completely covered with a preformed sheet of raw smoked rubber.

2. A paving element as claimed in claim 1 comprising a wood or other block to the longer sides of which are applied preformed sheets of raw smoked rubber, substantially as described.

3. A paving element comprising a. substantially rectangular block of comparatively hard material having applied to a plurality of its vertical sides in the form of a thin layer a pre-formed sheet of raw smoked rubber completely covering said sides.

4:. A paving element comprising a substantially rectangular block of comparatively hard material having applied to its vertical sides and ends in the form of a thin layer a preformed sheet of raw smoked rugber completely covering said sides and en s.

5. A paving element as claimed in claim '1 comprising a wood or other block the sides, ends and bottom of which are en'- veloped with preformed sheets of raw smoked rubber, substantially as described.

6. A load carrying surface comprising single block units composed of'a comparatively hard base material having applied thereto in the form of a thin layer a pre-formed sheet of raw smoked rubber completely covering a plurality of the vertical sides of the unit, said units being-laid in rows with the resiliently covered sides or sides and ends thereof in contact.

Signed at 52 Lincolns Inn Fields, London, W. C. 2, this fifth day of June, 1923' GEORGE FREDERICK UNDERWOOD. 

